Wheel truing device



Jan. 8, 1946-. R. A. MAHLMElSTE R WHEEL TRUING DEVICE Filed March 15, 1944 3 Sheets-Sheet 1 Jan. 8, 1946- R. A. MAHLMEISTER WHEELTRUING DEVICE- 3 Sheet-Sheet 2 Filed March 15, 1944 Jan. 8,v 1946. R. A. MAHLMEIYSTER WHEEL TRUING DEVYICE Filed March is, 1944 s Sheets-Sheet s MNVEN R u V m u. W s 1 A; M ggg am n 1 g m {WM i 8 w ATTORNEY Patented Jan. 8, 1946 WHEEL TRUING DEVICE Raymond A. Mahlmeister, Dayton, Ohio, assignor to The Sheflield Corporation, Dayton, Ohio, a

corporation of Ohio Application March 15, 1944, Serial No. 526,641

Claims. (01. 125-11) This invention relates to truing devices for grinding wheels.

One object of the invention is the provision of a grinding Wheel truing device of simple and compact construction and capable of operation over long periods of time with an accurate and exact control of the diamond holders by means of which the grinding wheels are trued at desired angles.

Another object is the provision of a truing device embodying a pair of diamond truing bars, slidably mounted in ofiset planes for movement at an angle to one another and operated by the same slidable part that engages the ends of both bars to positively advance them-in the general direction of the grinding wheel. i

Another object is the provision of a truing device of the character mentioned, in which'the diamond carrying bars are slidably arranged in a. pair of guide members that are pivotally ad- 'justable on a common axis on the support on which the'bars are arranged.

Another object is the provision of a truing device of the character mentioned, and having a third bar which is rotatable about its own axis to provide circular movement of its diamond to true a cylindrical surface on the grinding wheel.

Other objects and advantages of the invention will be apparent from the following description, the appended claims and the accompanying drawings, in which,

Fig. 1 is a side elevation of a grinding wheel truing device embodying the present invention;

Fig. 2 is a front elevation of the truing device; I

Fig. 3 is a bottom plan view;

Fig. 4 is a horizontal section on theline 4--4 of Fig. 1, and, Y I I Fig. 5 is a perspective view of one of the bar guide members and a cooperating spacerblock.

Fig. 6 is a vertical section on the line 66 of Fig. 2, immediately to the right of the cam 1|.

Referring more particularly to the drawings, in which the same reference numerals have been applied to lik parts in the several views, Ill designates a carrying bracket adapted to be mounted on the frame structure of a grinding machine which incorporates a, grinding wheel ll adapted to cut a V shaped groove or a screw thread on a workpiece. The carrying bracket in may be arranged so that the truing diamonds, and thesupport l2 which contains the operating mechrying bracket l0 so that the entire support l2 can be moved to a truing position or raised'to a withdrawn position above the grinding wheel as shown in Fig. l. The bracket ID is thus'provided with guideways i4 in sliding engagement with the face of the support. 'Fixedonthe support is a threaded screw [5 the lower end of which extends through. guiding 'lugs IS on the bracket and is threaded in an adjusting nut I'I. Fixed on the nut I! is a worm gear I8 operated 'by a worm l9 which is fixed to shaft carrying :a hand wheel 2|; By turning this handwheel. the nut I1 is rotated to move the threaded screw- [5 together with the support l2 to a desired position. l

The support 1 2 rotatably carries a control mem ber 23. In the embodiment of the invention dis-.

. wheel. Any suitable contour of substantialiy'v shape can be given to the grinding wheel,'but in the particular form of the invention disclosed, thegrinding wheel is adaptedfor cutting screw threads, preferably of the acme type.

Support l2 has spaced parallel walls 29 and 30 and between these walls is a pair of guide members shown as guide blocks 3i and 32 having flat surfaces abutting against the respective side walls. Arranged between the two guide blocks "are .two spacing blocks 33 and 34.' Screws '35 secure each guide block to the adjacent spacing block, and the distance between the walls 29 and 30 .is such as to just about receive the blocks 3| to 34 inclusive. 'With the bottom cover plate 36 removed, these four blocks may be moved upwardly-into position and pivot studs 31 and 38 are then insorted into the holes 39in the support walls and holes 40 in the guide blocks so that the two guide blocks are thus mounted for individual pivotal adjustment about a-='comm on axis lying in the plane of symmetry of the grinding wheel. Screws anism for the diamonds, is located vertically above 4i hold the pivotfstuds'in position. Set'screws 43 and 44 threaded inlthe support engage-against step portions 45 and 46 on'the respective blocks 3| and 32 to. provide for convenientadjustment from the exterior of..the support, of the angular positionof the two guide members. Springs, 48

engaging the cover plate 36 and arranged in sock-y ets 49 in the two guide members serve to hold the step portions of the guide members against the set screws. The guide block 3 I, spacing block 33 and the side wall 29 of the support l2 are provided with arcuate slots 50 concentric'with the pivot studs 31 and 38 and receiving a pair of clamp screws -the heads of which pressj against the outer .side of the wallv .29., These screws are threaded into the spacing plate 34 which has threaded openings 52 to receive them. Since the spacing plate 34 is secured by the screws 35 to the guide block 32, when the screws 5| are tightened all of these parts are held. firmly to one another in the position to which they are adjusted. I

The guide block 3| is provided with an inclined groove 54 which slidably receives the diamond carrying bar 55, which ils'preierably oi rec tangular cross section. The end of this bar car ries a boss 56 in which the diamond '24 is removahly supported infixed position thereon. The spacing block 33 retains the-bar 55' "with aslidmg fit on the side of the har. .At the upper end.

ofthe bar 55 is an offset head 5'! having a cam 510122581 which receives a camming pin 55 on camplate 50, the latter being: slidably supported for movement towards and from. "the grinding wheel axis, as will be presently described The head 51 on the: upper end. of the:..bar 55 carries a. pin SI; and surrounding the pin. is a compression springv 6.2 bearing against the head 51' at its upper end, with'the lower and of the spring arranged in a. hole 63 in: the block: 3!. This hole 63 and the pin .61 extend parallelv to the longitudinal axis of the bar 55, as will be apparent from 1- and In a manner, the guide block 32 and its cooperating spacing block: 34 slidably' support-the second bardii'havmg; the diamond 25, although the angle of inclination of the groovein which this: bar arranged is inclined in the opposite. direction, or downwardly and to the left as-ciewed in Big. 11.. The-51911 56 in head of this bar is ngaged by the; camming. pin 65!- which also provided in fixed; position on: the. cammingplate 60a.- As will-.nowbe apparent, when tl-ie eammingplatei moves downwardly from a position in Fig. ll, thepin-s: 5.9 and 61 will force the two head portions of the two bars downwardly; the. cammmg: pins operating in. the slots 58 and E6; and causing exactly the same.- movesment of the two bars: generally? a direction to.- wards thegriniiihgt wheeii. The angles. in which the tnuihg points more may be. exactlythesame with. respect tct the grinding. wheel. axis, hut at oppositesides of the plane: of. symmetry oi the.

grindingwheel, one'of these angles may be isfixed on shaft: Til having the control means .or handi'wh'eer as. the hand wheel is rotated through onerevolution. the. can It. causes the plate 60; to travel downwardly and back again; thus. advancing and then. retracting; the tming diamonds. Before the.- hand wheel; 13- is rotated. theJother hand. wheel 2.1 is adi usted to bring thediamonds dam toapredetermmed position' so that a cut: of: the.- desired depth. wilt be taken on the grinding wheel;

For truing a grinding wheel that is adapted to cut standard V shaped threads, the two diamonds as previously described are all that are required. Where the device is for use with grinding wheels that cut threads of the acme type, a third bar is provided in the support so that it can rotate about its own axis to give a circular movement. of its diamond and thus true a cylindrical surface, shown at M in Fig. 1, "I3 indicates the diamond that accomplishes this. It is carried at the end of a rotatable bar 15, guided at its lower end in a bearing 16 and at its upper endin a'bearing sleeve 11 which is held by a screw 18 on the support I 2., This bar extends through a wide slot or passage 84 provided in the spacing blocks 34. A compression spring 19 is seated at its lower end on an in-turned boss or .fiange on the sleeve 11 the upper end of the spring engaging the overhanging portions of a plate 80 which is fixed to the upper end of the bar 15. This. spring thus holds the bar-yieldingly in its retracted position against an adjust.- able cup 8|... The position of the cup 8.1 is-oontrolled by athreaded stud 82: operated by hand knob 83 to vary the location of thew-geometric planev containing the. circular orbit in. which the diamond. I3 operates- Fixed against. rotation on the bar [5 is an operating pinion 85.. The hub portion of this pinion is provided: with. a slot 8-6.- engaged by a pin- 81 on bar 15 so that the bar can. move longitudir nally without requiring corresponding. longitudinal movement of the. pinion. This pinion is in mesh with. an. operating gear 818' fixed on control shaft 12 so that as the control shaft 12- is turned and operates the cam 14 tooscillatethe cam plate 6 0,. it also rotates the bar 15 and thus causes the diamond 15 to turn in a circular orbit and face the: cylindrical surface on the grinding wheel. One revolution of the hand wheel '23 is arranged to produce acomplete revolution of bar 15 thus causing a complete circular movement of. the diamend 13..

The orbit of the diamond. 13 is contained a plane parallel to. the axis of the grinding wheel,

and the. axis of the. bar: L5 extends perpendicular tothe axis of th grinding wheel so that these axe -intersect. The extent to. which the diamond 1-3; is. offset from the. axis of the bar His-such thatv the. diameter of. its orbit.v is substantially- While the form. of apparatus herein described constitutes a preferred embodiment of the invention it is. to beunderstood that the invention is not limited to this. precise. form oi apparatus, and that changes may be made therein without departing fromthe scope of the invention which is defined in. the appended claims.

What is claimed is:

l- Atruing device. for grinding wheels, adapted iorpredeterminedpositioningon agrindingnwheel supporting; means, said truing device comprising. a support,v apair of guide members pivotally ad.- iustables on. said. support. for movement about a common axis lying in the plane of the grinding wheel; a pair: of. bars each slidahly: mounted for longitudinal movement in a guide member and each having a truing point, said bars being movable at an angle to one another and to the grinding wheel axis, means for adjustably locating each of said guide members on said support to locate the direction of movement of said bars in accordance with the angle desired on the grinding wheel, a common cam plate for simultaneously moving said bars longitudinally in the same general direction to true the wheel, a third bar rotatably mounted in said support for movement about a longitudinal axis extending perpendicularly to the grinding wheel axis, said bar having a truing point for truing a cylindrical surface on the wheel, a rotatable control member, means for rotating said third bar from the control member, and means operated by said control member for oscillating said cam plate.

2. A truing device for grinding wheels, adapted for predetermined positioning on a grinding wheel supporting means, said truing device comprising a support having parallel spaced walls, a pair of guide blocks arranged between said Walls and pivotally adjustable on said support for movement about a common axis lying in the plane of the grinding wheel, spacing means between said guide blocks, a pair of bars each slidably mounted for longitudinal movement in a guide member and each having a truing point, said bars being movable at an angle to one another and to the grinding wheel axis, an arm rigid with each of said guide blocks and arranged adjacent one another, and a pair of adjusting screws threaded in said support and respectively engaging said arms for adjustably locating each of said guide blocks on said support to locate the direction of movement of said bars in accordance with the angle desired on the grinding wheel, a cam plate guided in said support and engaging the ends of both of said bars and a rotatable cam for moving said cam plate to simultaneously and 4 equally move said bars in the same general direction to true the wheel.

3. A truing device for grinding wheels, adapted for predetermined positioning on a grinding wheel supporting means, said truing device comprising a support having parallel spaced walls, a pair of guide blocks arranged between said walls and pivotally adjustable on said support for movement about a common axis lying in the plane of the grinding wheel, spacing means between said guide blocks, a pair of bars each slidably mounted for longitudinal movement in a guide member and each having a truing point, said bars being movable at an angle to one another and to the grinding wheel axis, means for adjustably locating each of said guide members on said support to locate thedirection of movement of said bars in accordance with the angle desired, a third bar rotatably mounted in said support for movement about a longitudinal axis extending perpendicularly to the grinding wheel axis, said bar having a truing point for truing a cylindrical surface on the wheel, said spacing means having a passage through which said third bar extends, and means for simultaneously rotating said third bar and reciprocating said other two bars to true the wheel.

4. A device adapted for predetermined positioning on a grinding wheel support, for truing adjacent inclined faces and a short cylindrical face on a grinding wheel, said device comprising supporting means, a pair of bar members, said supporting means having passages in ofiset planes in which said bar members are longitudinally operable at an angle to one another and to the grinding wheel axis, each of said bar members having a wheel truing point adjacent one end thereof, a common means for operating both of said bar members longitudinally in the same general direction for simultaneously truing inclined faces on the grinding wheel, a bar rotatably mounted in said support for movement about a longitudinal axis extending perpendicularly to the grinding wheel axis, said bar having a truing point arranged eccentric of the bar aXis for truing a cylindrical surface on the wheel, said bar having its axis perpendicular to and intersecting the axis of the grinding wheel, and means operated by said common means for rotating said barthrough a complete revolution to pass the diamond on said bar across the wheel face in one direction and then the other.

5. A truing device for grinding wheels, adapted for predetermined positioning on a grinding wheel supporting means, said truing device comprising a support, a pair of guide blocks pivotally adjusted on said support for movement about a common axis, means for adjusting said blocks, a pair of bars each slidably mounted for longitudinal movement in a guideblock and each having a truing point, said bars being movable at an angle to one another and to the grinding wheel axis, a part reciprocably operable in said support for simultaneously moving both of said bars,

a rotatable control member for reciprocating said part, a bar rotatably mounted in said support for movement about a longitudinal axis extending perpendicularly to the grinding wheel axis, said rotatable bar having a truing point arranged eccentric of the bar axis for truing a cylindrical surface; on the wheel, said rotatable bar having its axis perpendicular to and intersecting the axis of the grinding wheel, and an operating connection between said rotatable bar and said rotatable control member for rotating said bar through a complete revolution to pass the diamond across the wheel first in one direction and then the other. RAYMOND A. MAHLMEISTER. 

